The present invention relates to fluid-operated driving arrangements, and more particularly to improvements in driving arrangements of the type wherein a mass is movable (e.g., reciprocable) by a hydraulic motor whose working chamber or chambers can receive pressurized hydraulic fluid by way of a regulating valve and the fluid is or can be expelled from the working chamber or chambers in response to movement of the motor.
German Offenlegungsschrift No. 30 44 675 discloses a driving arrangement of the above outlined character. This publication further discloses the possibility of controlling the distance which is covered by and/or the velocity of the mass by an electronic control system through the medium of the regulating valve. Still further, the aforementioned publication discloses that, for the purpose of braking or decelerating the mass, the fluid which is expelled from the hydraulic motor can be admitted, at least temporarily, into an accumulator which serves to supply at least a certain percentage of pressurized hydraulic fluid that is needed for operation of the hydraulic motor. A drawback of the driving arrangement which is disclosed in the Offenlegungsschrift No. 30 44 675 is that it does not allow for an optimum recovery of energy which is released during deceleration of the mass.
German Auslegeschrift No. 12 25 012 discloses an accumulator which is designed to reduce the shocks that develop as a result of deceleration of a moving mass. This publication also fails to make any satisfactory proposals regarding the possibility or advisability of recovering maximum amounts of energy during deceleration of a mass which is reciprocable or otherwise movable by a hydraulic motor.